New Build Advice Commuter Sydney

[Dusty44]

Hi Guys,

I'm looking at adding electric assist to my commuter bike which is a 26" mountain bike frame. The aim is to cover the 11km each way trip in my work clothes and avoid breaking a sweat on the way in, there are some short steep hills in this trip which stop me from riding in my work clothes. I'm on a budget of $1000 and based in Sydney, I'd like to keep the build inconspicuous to avoid theft so was targeting geared hub motors.

From reading this forum I was landing on an em3ev setup as a good place to start for a first build - though it comes in over budget with shipping costs. Looking for suggestions to reduce cost from this build considering I'm based in Sydney so sourcing locally without shipping costs is a bonus but I would like to use components which will scale / last if I want to play with the bike further.

Anyone have a local battery solution they would recommend to avoid the high shipping costs?

Min Top speed aim: 25km/h
Distance: 22km

50V 10A
MAC 10T (low speed for the hills) upgraded version
6FET controller
C3 computer
PAS (to cover off local laws)
50 V Charger switchable
7sp freewheel (existing bike is 8 speed happy to go to 7)

Thanks,
Mike

 

[dogman dan]

It pains me to say it, but your ride is actually short enough to consider a 12 ah lead battery. Then charge at work. It will suck bad to carry all that weight though, and you'd have to ride very slow.

Just as cheap, would be a very small RC lipo pack. 5 ah should be just about enough, if you ride on the slower side. But I very seldom recommend that to the new guys, unless they show in some way that they have experience with RC batteries, or have a high degree of ability to practice a safety routine, like you have a pilots certificate.

Get the smaller, 25 amps controller. A larger controller makes sure you will spend more on a bigger battery. The best advice might be to get the motor now, then save up the bit more you need for a good, safe, easy to care for battery.

You might consider sunthing on Ebay, for a 36v 15 ah lifepo4. Other ebay sellers exist, but sunthing has the pouch cell packs that seem to last longer than round cell ebay bargian packs with flaky spot welds. This does not mean a better built round cell pack like EM3ev has this problem.

Last, you might look again at the direct drive kits. Yes, they look larger. but they hide behind a set of panniers just fine if you get a rear motor. They get up hills fine too. You save a few on the motor, you can afford a bit more battery.

 

[Drunkskunk]

Its hard to give a recomendation without knowing more about the hills you have to ride. Are you talking about hills like Attunga Street? If thats the case, no hub motor is going to work. you'll need to go with a chain drive. If you're dealing with more reasonable hills, you might be able to save some money with a direct drive hub.

 

[dogman dan]

One nice feature of ebikes, is that if there is a much longer less steep way, you can take it with little pain. I found myself often looking for the long way, a 15 mile ride home too short on the nicer days.

Back to the subject of RC batteries, I think Hobby King has an AU warehouse, so those ship from in country.

Is Hyena selling batteries? Might look at his website.

 

[wesnewell]

Unless you tell people you're in Sydney AU(?) every time please do this.
Welcome to ES****Do this before your first post or now (it's retroactive)*****
Please go to the User Control Panel, select Profile, and then enter your city, state/province, and country into the Location field (country minimum) and save it. This will help people help you. Example: Wylie, TX, USA. or just USA, but country as a minimum, and country is the most important. There are many cities with the same name all over the world. Without knowing what country you are in it's hard to make any recommendations. Thank you.
Pair this with 10ah of 12s lipo from HK Australia and it will climb any hill you have there.
http://www.ebay.com.au/itm/Electric-Bicycle-E-Bike-Conversion-Kit-Brushless-Motor48V-1000W-Rear-Wheel-Rack-/150956506830
http://www.ebay.com/itm/Waterproof-Digital-Voltmeter-DC-15V-To-120V-Red-Led-Voltage-Digital-Panel-Meter-/170846310527

 

[d8veh]

If you're on a tight budget, the Bafang BPM motor will be more than sufficient for what you want. You have to think about the speed vs climbing efficiency. In a 26" wheel, the 201 rpm 36v one will max out at about 17 mph at 36v and 23mph at 48v. The 328 rpm 36v one does 25mph at 36v. If you order the 328 rpm one, make sure that you select it and you have to tell them that it's important. The higher the speed you choose, the worse the efficiency when climbing, which can over-heat the motor. It's the same with any hub-motor.
The controllers in these kits can run with 36v or 48v. You need a battery that can give 30 amps:
http://www.bmsbattery.com/ebike-kits/347-bafang-350watts500watts-bpm-motor-e-bike-kit.html
http://www.bmsbattery.com/36v/445-36v-15ah-lithium-ion-electric-bicycle-battery-pack.html
http://www.bmsbattery.com/36v/450-a-pair-of-ebike-torque-arm.html
http://www.bmsbattery.com/accessory/459-hwbs-hidden-wire-brake-sensor.html

You'll have to add an additional $60 to cover the air freight surcharge. You get the shipping costs at the second step of the check-out. They seem expensive, but the overall cost is still cheap.

 

[Kabbage]

The aim is to cover the 11km each way trip in my work clothes and avoid breaking a sweat on the way in,

I know what you're saying dude - my reason for e-biking exactly. (But I've also lived in Sydney too, and in Summer you're going to get sweaty standing still, so don't be overly precious about that requirement!)

Anyone have a local battery solution they would recommend to avoid the high shipping costs?

I have not ever found anything satisfactory. I reckon you've got basically two choices; either
1. LiFeP04; either buy from Ping ready built, or if you're adventurous, get some Headways and a BMS as parts from evassemble.com and build it yourself. There's between $400-550 AUD.
2. LiPo; Hobbyking does have a local warehouse, and you can generally get the 5000mAh bricks for around $40 a throw - but it'll still end up costing you about $500 by the time you get the necessary charger and power supply for the charger (why the darn LiPo chargers need separate DC power supplies is beyond me...). These'll be smaller and lighter than the LiFePO4, but the risk is you'll burn your house down if you're not 'careful' with them, and you'll get much fewer cycles (800ish quoted) (and have to replace them) than the LiFePO4 (3000 cycles potentially).

You'll need probably 12Ah of battery to be safe, but you may get away with 10 if you're careful.

Min Top speed aim: 25km/h
Distance: 22km

50V 10A

I think you'll want 20 amps for those hills, at least. User BenMoore (in Melbourne) does a 50A controller for about $35 - bargain. (and he sells the Bafang BPM500W motors, either nude or laced into a reasonable rim). PM him.

MAC 10T (low speed for the hills) upgraded version
6FET controller
C3 computer

If you're trying to go cheap-as-chips, consider if you actually need the CA3 computer... I used mine a bit when I first started to get a feel for things, but eventually you never really look at it. My latest build has no computer - I don't miss it.

PAS (to cover off local laws)
50 V Charger switchable
7sp freewheel (existing bike is 8 speed happy to go to 7)

You're already probably strictly non-compliant, so why would you want to have a PAS? You can get a thumb or twist throttle for $15 from BenMoore (and a 7sp freewheel). Experience suggests, perhaps, ditching the rear deraillier completely and going three-speed on the front chainrings only. It works surprisingly well. I had a 7 speed on my rear for a start on my first build, and never really used it. You'll need to get a freewheel anyway, as all these motors don't take gear clusters for freehubs (or you could see if you could get one of the newer motors from Bafang that do - and keep your 8 speed).

Only thing I reckon you've forgotten is lights - if you're going to be commuting 'all season' - either some from a LBS, or if you want integrated, get some of the 10-100V capable lights from ebikes.ca - they're sweet, but $$$ ($165front/$65 rear from memory).

 

[wesnewell]

For only 22km, 10ah of 12s lipo will be plenty. That'll cost you ~$200. A 12s charger will run you $90. A power supply, from nothing using an old pc psu, to maybe $50 for a 350w 12-15v psu. Total cost including motor kit,battery pack, and charging supplies will be about $600.

 

[Samd]

Not sure what hills you're tackling, and how fast you want to go, or accelerate.
Hobbyking AU is ok. But for my work bike I just use a q100 front kit with a 9Ahr 15amp bottle battery. It's not my offroad bike or my cargo bike, but it's a nice commuter.

Cheers.